1. Technical Field
The present invention relates generally to an improved data processing system and in particular to a method and apparatus for processing data. Still more particularly, the present invention relates to a method, apparatus, and computer instructions for transmitting packets from a source to a target.
2. Description of Related Art
In network data processing systems, remote wake-up abilities are often provided for clients. This type of feature allows a client to be turned on through the network. With this feature, a system administrator or other user may wake up a sleeping client by sending a network packet. For example, with a network adapter, such as an Ethernet controller, the adapter is modified to listen for a special wake-up on local area network (LAN) address even when the computer in which the network adapter is located is asleep in a power conservation mode. Upon receiving this packet, the network adapter checks the packet content to ensure that the packet is destined for this particular client. If the packet is destined for the client, the adapter wakes up the sleeping clients.
This type of feature may be used on a large network data processing system in which the system administrator's data processing system is located on a different subnet from the clients that are being managed. In this case, the “wake-up” packet may be forwarded by routers along the way to the client from the system administrator's data processing system. With the current version of Internet Protocol version 4 (IPv4), this forwarding of packets is managed by sending the “wake-up” packet to an IPv4 subnet-directed broadcast address for the machine that is to be woken up. When this packet reaches the router at the subnet for the target client, the router simply forwards this subnet-directed broadcast packet to the final subnet where the packet is picked up by the network adapter of the client that is to be woken up.
With Internet Protocol version 6 (Ipv6), such a mechanism does not work. This version of Internet Protocol (IP) and other types of protocols do not support subnet-directed broadcast addresses. Therefore, it would be advantageous to have an improved method, apparatus, and computer instructions for waking up a sleeping client on an IPv6 network data processing system.